POE::Component::Server::SMTP - SMTP Protocol Implementation

  use POE;
  use POE::Component::Server::SMTP;

  POE::Component::Server::SMTP->spawn(
    Port => 2525,
  	InlineStates => {
  		HELO => \&smtp_helo,
  		QUIT => \&smtp_quit,
  	},
  );

  sub smtp_helo {
    my ($heap) = $_[HEAP];
    my $client = $heap->{client};

    $client->put( SMTP_OK, 'Welcome.' );
  }

  sub smtp_quit {
    my ($heap) = $_[HEAP];
    my $client = $heap->{client};

    $client->put( SMTP_QUIT, 'Good bye!' );
    $heap->{shutdown_now} = 1;
  }

  $poe_kernel->run;
  exit 0;

	SMTP_SYTEM_STATUS SMTP_SYSTEM_HELP SMTP_SERVICE_READY SMTP_QUIT
	SMTP_OK SMTP_WILL_FORWARD SMTP_CANNOT_VRFY_USER

	SMTP_START_MAIL_INPUT

	SMTP_NOT_AVAILABLE SMTP_SERVICE_UNAVAILABLE
	SMTP_LOCAL_ERROR SMTP_NO_STORAGE

	SMTP_SYNTAX_ERROR SMTP_ARG_SYNTAX_ERROR SMTP_NOT_IMPLEMENTED
	SMTP_BAD_SEQUENCE SMTP_ARG_NOT_IMPLEMENTED SMTP_UNAVAILABLE
	SMTP_USER_NOT_LOCAL SMTP_QUOTA_LIMIT SMTP_MAILBOX_ERROR
	SMTP_NO_SERVICE SMTP_TRANSACTION_FAILED

package POE::Component::Server::SMTP;
use strict;

use Exporter;
use Mail::Internet;
use Sys::Hostname qw[hostname];
use POE qw[
	Wheel::ReadWrite
	Driver::SysRW
	Filter::SMTP
	Filter::Line
	Session::MultiDispatch
	Component::Server::TCP
];

use vars qw[$VERSION @ISA @EXPORT];
$VERSION = '1.6';
@ISA     = qw[Exporter];
@EXPORT  = qw[
	SMTP_SYTEM_STATUS SMTP_SYSTEM_HELP SMTP_SERVICE_READY SMTP_QUIT
	SMTP_OK SMTP_WILL_FORWARD SMTP_CANNOT_VRFY_USER

	SMTP_START_MAIL_INPUT

	SMTP_NOT_AVAILABLE SMTP_SERVICE_UNAVAILABLE
	SMTP_LOCAL_ERROR SMTP_NO_STORAGE

	SMTP_SYNTAX_ERROR SMTP_ARG_SYNTAX_ERROR SMTP_NOT_IMPLEMENTED
	SMTP_BAD_SEQUENCE SMTP_ARG_NOT_IMPLEMENTED SMTP_UNAVAILABLE
	SMTP_USER_NOT_LOCAL SMTP_QUOTA_LIMIT SMTP_MAILBOX_ERROR
	SMTP_NO_SERVICE SMTP_TRANSACTION_FAILED
];

sub SMTP_SYTEM_STATUS          { 211 }
sub SMTP_SYSTEM_HELP           { 211 }
sub SMTP_SERVICE_READY         { 220 }
sub SMTP_QUIT                  { 221 }
sub SMTP_OK                    { 250 }
sub SMTP_WILL_FORWARD          { 251 }
sub SMTP_CANNOT_VRFY_USER      { 252 }

sub SMTP_START_MAIL_INPUT      { 354 }

sub SMTP_NOT_AVAILABLE         { 421 }
sub SMTP_SERVICE_UNAVAILABLE   { 450 }
sub SMTP_LOCAL_ERROR           { 451 }
sub SMTP_NO_STORAGE            { 452 }

sub SMTP_SYNTAX_ERROR          { 500 }
sub SMTP_ARG_SYNTAX_ERROR      { 501 }
sub SMTP_NOT_IMPLEMENTED       { 502 }
sub SMTP_BAD_SEQUENCE          { 503 }
sub SMTP_ARG_NOT_IMPLEMENTED   { 504 }
sub SMTP_UNAVAILABLE           { 550 }
sub SMTP_USER_NOT_LOCAL        { 551 }
sub SMTP_QUOTA_LIMIT           { 552 }
sub SMTP_MAILBOX_ERROR         { 553 }
sub SMTP_NO_SERVICE            { 554 }
sub SMTP_TRANSACTION_FAILED    { 554 }

sub spawn {
	my ($class, %args) = @_;

	$args{Alias}         ||= 'smtpd';
	$args{Hostname}      ||= hostname();
	$args{Port}          ||= 25;

	$args{PackageStates} ||= [ ];
	$args{ObjectStates}  ||= [ ];
	$args{InlineStates}  ||= { };

	POE::Component::Server::TCP->new(
                Address            => $args{Address},
		Alias              => $args{Alias},
		Port               => $args{Port},
		SessionType        => 'POE::Session::MultiDispatch',
#		SessionParams      => [ options => { debug => 1, trace => 1 } ],
		Error              => \&smtpd_server_error,
		ClientConnected    => \&smtpd_client_connected,
		ClientDisconnected => \&smtpd_client_disconnect,
		ClientInput        => \&smtpd_client_input,
		ClientFlushed      => \&smtpd_client_flushed,
		ClientError        => \&smtpd_client_error,
		ClientFilter       => [ 'POE::Filter::SMTP' ],
		PackageStates      => $args{PackageStates},
		ObjectStates       => $args{ObjectStates},
		InlineStates       => {
# these are shown below for reference and may move elsewhere
#			send_banner => \&smtpd_send_banner,
#			HELO        => \&smtpd_HELO,
#			QUIT        => \&smtpd_QUIT,
#			DATA        => \&smtpd_DATA,
#			gotDATA     => \&smtpd_gotDATA,
			_default    => \&smtpd_default,
			%{$args{InlineStates}},
		},
		Args => [ \%args ],
	);

}

sub smtpd_client_connected {
	my ($kernel, $heap, $args) = @_[KERNEL, HEAP, ARG0];
	my ($client) = $heap->{client};

  $heap->{args} = $args;

	$kernel->yield( 'send_banner' );
}

sub smtpd_client_disconnect {
	my ($kernel, $heap) = @_[KERNEL, HEAP];
	$kernel->yield( 'do_disconnect' );
}

sub smtpd_client_input {
	my ($kernel, $heap,    $input) = @_[KERNEL, HEAP, ARG0];
	
	if ( $heap->{+SMTP_START_MAIL_INPUT} ) {
		my $client = $heap->{client};
		if ( $input eq '.' ) {
			$heap->{+SMTP_START_MAIL_INPUT} = 0;
		  $client->set_input_filter( POE::Filter::SMTP->new() );
		  $kernel->yield( gotDATA => $heap->{data_input} );
		} else {
			push @{$heap->{data_input}}, $input;
		}
	} else {
		my ($client, $command, $data)  = ( $heap->{client}, @{$input} );
		$kernel->yield( $command => $command => $data );
	}
}

sub smtpd_client_flushed {
	my ($kernel, $heap) = @_[KERNEL, HEAP];

	delete $heap->{client} if $heap->{shutdown_now};
}

sub smtpd_client_error {
	my ($kernel, $heap, $syscall_name, $error_number, $error_string) =
		@_[KERNEL, HEAP, ARG0 .. ARG2];
}

sub smtpd_server_error {
	my ($kernel, $heap, $syscall_name, $error_number, $error_string) =
		@_[KERNEL, HEAP, ARG0 .. ARG2];
}

sub smtpd_send_banner {
	my ($kernel, $heap) =
		@_[KERNEL, HEAP];
	my $client = $heap->{client};

	my $banner = join( ' ',
		                 $heap->{args}->{Hostname},
		                 'ESMTP',
		                 __PACKAGE__,
		                 'v'.$POE::Component::Server::SMTP::VERSION );

	$client->put( SMTP_SERVICE_READY, $banner );
}

sub smtpd_HELO {
	my ($kernel, $heap, $host) =
		@_[KERNEL, HEAP, ARG1];
	my $client = $heap->{client};

	if ( $host && $host eq $heap->{args}->{Hostname} ) {
		$client->put( SMTP_OK, qq[$heap->{args}->{Hostname} Would you like to play a game?] );
	} else {
		$client->put( SMTP_ARG_SYNTAX_ERROR, qq[Syntax: HELO hostname] );
	}
}

sub smtpd_QUIT {
	my ($kernel, $heap) =
		@_[KERNEL, HEAP];
	my $client = $heap->{client};

	$client->put( SMTP_QUIT, q[How about a nice game of chess?] );
	$heap->{shutdown_now} = 1;
}

sub smtpd_DATA {
	my ($kernel, $heap) =
		@_[KERNEL, HEAP];
	my $client = $heap->{client};

	$heap->{+SMTP_START_MAIL_INPUT} = 1;

	$client->put( SMTP_START_MAIL_INPUT, q[You selected Global Thermo Nuclear War.] );
	
	$client->set_input_filter( POE::Filter::Line->new( Literal => POE::Filter::SMTP::CRLF ) );
}

sub smtpd_gotDATA {
	my ($kernel, $heap) =
		@_[KERNEL, HEAP];
	my $client = $heap->{client};
	my $data   = join POE::Filter::SMTP::CRLF, @{$heap->{data_input}};
print $data;
	$client->put( SMTP_OK, q[Got data.] );
}

sub smtpd_default {
	my ($kernel, $heap) =
		@_[KERNEL, HEAP];
	my $client = $heap->{client};

	$client->put( SMTP_NOT_IMPLEMENTED, q[Error: command not implemented] );
}

1;

__END__